CAIRO: Gunmen attacked a packed mosque in Egypt's restive North Sinai province on Friday and set off a bomb, killing at least 155 people in one of the country's deadliest attacks in recent memory, state media reported.

A bomb explosion ripped through the Rawda mosque roughly 40 kilometres west of the North Sinai capital of El-Arish before gunmen opened fire on the worshippers gathered for weekly Friday prayers, officials said.

State television reported at least 155 people were killed and 120 wounded in the attack, which is unprecedented in a four-year insurgency by militants groups.

The Islamic State group's Egypt branch has killed hundreds of policemen and soldiers, and also civilians accused of working with the authorities, in attacks in the north of the Sinai peninsula.

They have also targeted followers of the mystical Sufi branch of Sunni Islam as well as Christians.

The victims included civilians and conscripts praying at the mosque.

A tribal leader and head of a Bedouin militia that fights IS told AFP that the mosque is known as a place of gathering for Sufis.

The Islamic State group shares the puritan Salafi view of Sufis as heretics for seeking the intercession of saints.

The militants had previously kidnapped and beheaded an elderly Sufi leader, accusing him of practising magic which Islam forbids, and abducted Sufi practitioners later released after "repenting."

The group has killed more than 100 Christians in church bombings and shootings in Sinai and other parts of Egypt, forcing many to flee the peninsula.

IS regularly conducts attacks against soldiers and policemen in the peninsula bordering Israel and the Palestinian Gaza Strip, although the frequency and scale of such attacks has diminished over the past year.

Aside from IS, Egypt also faces a threat from Al-Qaeda-aligned militants who operate out of neighbouring Libya.

Many of those killed belonged to the interior ministry's secretive National Security Service.

The military later conducted air strikes on the attackers, killing their leader Emad al-Din Abdel Hamid, a most wanted militants who was a military officer before joining an Al-Qaeda-affiliated group in Libya's militant stronghold of Derna.—AFP